3D printing some of the world’s lightest materials

Host: Nick Howe

Welcome back to the Nature Podcast. This week, 3D printing ultralight insulators…

Host: Shamini Bundell

And a transition from a liquid to a liquid. I’m Shamini Bundell.

Host: Nick Howe

And I’m Nick Howe.

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Host: Nick Howe

As you might by now be aware, our coronavirus-specific segment, Coronapod, will be appearing later on in the podcast. If you’re just here for that, I’ll put the timings in this week’s show notes so you can skip straight to it, but if I were you I would stay right here, as there’s plenty of interesting non-corona science coming up.

Host: Shamini Bundell

There is, and kicking us off, reporter Benjamin Thompson has been looking at a new way to 3D print a material with some rather remarkable properties.

Interviewer: Benjamin Thompson

If you dig back into the archives of Nature, going all the way back to 16 May 1931 no less, you’ll find a short article describing a process to remove the liquid trapped inside a gel and replace it with air, creating a solid substance known as an aerogel.

Interviewee: Shanyu Zhao

Aerogel is quite an exceptional material, and it’s like a super porous, lightweight material, which is composed of over 90% air by volume, so it is one of the lightest solid materials in the world.

Interviewer: Benjamin Thompson

This is Shanyu Zhao who researches aerogels. He’s not kidding either. These things are really light. If you do a quick search online, you’ll see blocks of aerogel resting on top of flower petals, for example. It’s this structure that Shanyu describes of a scaffold containing countless microscopic pores of air that makes them so light, but it also gives aerogels another useful property – they are incredible thermal insulators. This week in Nature, he and his colleagues have published a new way to 3D print silica-based aerogels – the most widely used form of the material – which could open up new possibilities to take advantage of their properties. In recent years, NASA has taken advantage of silica aerogel’s insulating abilities to help protect the delicate components on board some of the rovers they send to Mars. But the vast majority of silica aerogels are used back here on Earth, as Wim Malfait, a co-author on the paper, explains.

Interviewee: Wim Malfait

They are often discussed in terms of these aerospace applications because historically NASA has done a lot of development there, but the actual real application that there is a real volume of use is in thermal insulation for oil and gas pipelines – that was certainly the original market – and more lately, also, just building insulation. So, there is an actual substantial market in the order of hundreds of millions of dollars a year of actual silica aerogel production and consumption.

Interviewer: Benjamin Thompson

However, this insulating ability doesn’t come without cost. It turns out that this structure that makes silica aerogels so useful also makes them fantastically brittle. Here’s Shanyu.

Interviewee: Shanyu Zhao

You can imagine, while the material has over 90% of the air, on the other hand, it’s less than 10% solid inside, so then, of course, it’s very weak, so you even can smash it to a powder very easily by hand.

Interviewer: Benjamin Thompson

This fragility means it’s really hard to use tools to machine down blocks of silica aerogel into smaller or more complex shapes. But rather than taking a silica aerogel and cutting it down to size, Shanyu and his colleagues have gone the other way and developed a new aerogel ink that can be 3D printed to make miniature shapes from the ground up – a tricky thing to do when dealing with a material that’s so fragile. The team used a process known as direct ink writing, which has been around for a while. The inks used in this process have to be able to change their behaviour as they’re being printed.

Interviewee: Shanyu Zhao

Before printing, the ink needs to be highly viscous. Then when you squeeze it, it should be like liquid so that it can easily go through a nozzle and then, after printing, the viscosity needs to go very quickly up, so that you can keep the good shape of the filaments printed from the nozzle.

Interviewer: Benjamin Thompson

To achieve the perfect prints with their aerogel ink, the team added a crushed-up powder of pre-existing aerogel to a suspension of silicon nanoparticles. The powder provided the ink’s ability to change from viscous to squeezable and back to viscous again, while the nanoparticles ultimately coalesced into the printed object’s scaffold, forming aerogel powder trapped within an aerogel. The combination of these two ingredients meant that the team could print objects made of just silica aerogel – something not done before. So, with the functioning ink in hand, the team wanted to put it through its paces. Shanyu says that an ideal place to start was by making miniature thermal insulators to fit on circuit boards where space is often limited.

Interviewee: Shanyu Zhao

The first idea, we want to print, basically, different thicknesses or shapes which can be applied, for example, on the circuit board, and then we can mitigate the hotspot, and these materials could also be useful to protect some more sensitive components.

Interviewer: Benjamin Thompson

The team printed an insulating cap just over a millimetre thick that could protect a delicate, heat-sensitive capacitor better than an equivalent cap made of polystyrene. Wim Malfait, who you heard from earlier, says that miniaturised insulation applications like this are likely where this 3D printing ability will be used first, and they’re talking to companies about it. But in this work, the team also showed that by adding different compounds to their ink mix, they could print objects with different characteristics. For example, by sandwiching a layer of aerogel with added manganese dioxide on top of one without, they were able to produce a miniature gas pump with no moving parts. Wim thinks that printing objects with different properties is the future of this technology, but it’s a way off just yet.

Interviewee: Wim Malfait

The functionalisation application, I think, there, the 3D aspects could really come into it. I think if we have multi-ink printing where we can have different functionalities in a single object, that’s I think more on, let’s say, the academic level for now, trying to see how far we can push it in that direction. There’s more science to be done and more thinking to be done from us but maybe also from other people who are interested in developing applications with us.

Host: Shamini Bundell

That was Wim Malfait. You also heard from Shanyu Zhao. Both are from the Swiss Federal Laboratories for Materials Science and Technology, and you can find a link to their paper in the show notes.

Host: Nick Howe

Next up on the show, it’s time for Coronapod, where Benjamin Thompson is back again, along with Noah Baker and Amy Maxmen, to discuss the latest coronavirus updates. And if you want to skip ahead to the non-corona content, the show notes have timings for everything else that’s coming up. Over to you, Benjamin.

Host: Benjamin Thompson

Yes, that’s right. It’s time, once again, for Coronapod and, once again, I’m joined by Amy Maxmen and Noah Baker. Hello to you both.

Amy Maxmen

Hi.

Noah Baker

Hello there.

Host: Benjamin Thompson

This week, we’re going to be talking about the availability of data during the pandemic – something we’ve touched on before and, of course, very, very important – and Amy, this is something that you’ve been reporting on.

Amy Maxmen

Well, yeah, so the reason I was really interested in this is I always think, how is it possible that we’ve had more than 5.4 million cases in the US and there’s still kind of no great answers on how safe it is to go to the grocery store or how safe cashiers are to work in the grocery store. In other outbreaks – for example, I was in West Africa during the Ebola outbreak – often there might be some basic data collected when somebody tested positive, like, ‘Were you at a funeral? Did you take care of somebody that had Ebola?’ Basic information that would let epidemiologists figure out where people are getting infected and therefore where they can kind of make solutions that will plug those holes.

Noah Baker

So, this is kind of what we’ve been talking about a lot when it comes to contact tracing. So, there’s this idea that when you test positive, you can then be contacted by a contact tracer, and all of your interactions with people over a period of time can be monitored and those people can be contacted. But there’s kind of a step beyond just tracing that for epidemiologists, which is trying to make that data publically available in some format as well so that other people that haven’t had a direct interaction with a contact tracing system could still look and see, ‘Hey, this particular place in my town or this particular type of event is a hotspot for stuff that I should stay clear of right now,’ and that’s the kind of thing that can be really, really useful. And I have to say, I was also kind of interested that that doesn’t seem to be very prominent. Certainly in the UK, I struggle to find out what the R rate in my own city is, let alone like any kind of detailed information about where may or may not be safe to travel to at the moment.

Amy Maxmen

Yeah, there’s like a whole bunch of categories of information. One is, right, if there’s contact tracing, you have a sense of what are the clusters of where outbreaks are occurring. If you’re in touch with people who might be infected, they have a good sense of their risk. But then contact tracing isn’t exactly the same as where somebody was exposed because contact tracers might figure out somebody’s history up to two days before they showed symptoms. It doesn’t necessarily ask where they got infected, so this is sort of a different category of information. And then there’s types of data that give you a sense of what’s the situation for coronavirus, what’s the rate of transmission in the area that you’re living in, and that can be a number of things like, ‘What is the percent of tests that have been positive?’ That gives you a good sense of what’s going on.

Host: Benjamin Thompson

And if these sorts of data were collected and widely available, presumably it would allow public health officials to do targeted responses rather than the sorts of blanket lockdowns that we’ve seen in some places.

Amy Maxmen

Exactly, so, in a way, having this data actually means you may not have to be so restricted everywhere. I talked to an infectious disease doctor who works in a hospital in Vallejo, which is sort of a lower-income community about a half hour from where I live. He was saying he’s treated around 50-60 severe COVID patients, and he’ll, kind of as a matter of routine, just sort of ask them how they think they got it, and he said most people he’s talked to seem like they either work in construction or they work at a food processing plant or they’re dating somebody who was in those professions or they share a household with somebody in those professions. But it’s not like this is like a form that he fills out and just sends to the health department. It’s not really clear if anybody’s routinely collecting this sort of data. And he’s just saying knowing that could be really helpful because maybe the health department in Vallejo might decide that if construction is the major source of infection, the kind of measures they might do to try and limit spread might be different than in another area where we find that there’s a massive university outbreak or people are having parties.

Noah Baker

Do you have any ideas why that data isn’t being routinely collected? I mean I guess that’s a really big question, but I feel like on Coronapod, for months now, we have been saying the more data we can have, the better we can manage, and I think any scientist listening to this will also very much be in favour of gathering more data. And it’s not like people haven’t been focused on this problem for quite a long time and yet they’re not gathering that data. Is it just because the kind of people that maybe would need to are health workers and they’re overwhelmed with just keeping people alive or is it just because there’s – I’m going to guess at the words that you tend to use in this situation in the States – lack of leadership?

Amy Maxmen

Yeah, both of those are correct, and more. I think one problem is that while data science has seen immense growth in the past 5-10 years, it really hasn’t altered public health. That data system really has not been updated for a very long time. And then also, it just is really fragmented. So, for example, a doctor like the doctor I just mentioned in Vallejo, he might take note of things like a person’s race and their age and their occupation and how they were exposed in their health record at the hospital, but then he sends their sample to a testing lab and then the testing lab is the one that often reports whether a case is positive to the health department, but that report doesn’t come with all of the other information that he’s recorded in the health record. We see lots of missing data that we know is really important to even understanding who’s affected in this outbreak. This is sort of why the system has really broken down and health departments, a lot of them, are underfunded, so by the time they’ve kind of managed to cobble all this data together, there’s really not enough people there to clean it up and do analyses of it. There’s plenty of really good epidemiologists at universities who I’ve talked with, but a lot of them have not gotten any luck when they try and request access to data from health departments because they would love to try and do this sort of big data crunching so that we could get answers, but they’ve been told no, at least here in California. I saw some of the emails between the director of the health department in California and researchers at a number of universities in California, including like University of California, San Francisco, and there the idea is, ‘Oh, well, it’s private data.’ They’ve asked for it to be de-identified, they’ve said you don’t have to give exact location, just approximate location, but they’re not getting the data that they need.

Host: Benjamin Thompson

And yet with all this fragmentation that’s going on, there are a lot of unofficial data sources – and I use that word carefully – that people are using. We’ve talked about them on the podcast here before.

Amy Maxmen

Yeah, so that’s sort of who’s picked up the slack, non-governmental places, and that’s everything from media reports – a lot of times when we hear about outbreaks in the US it’s because a newspaper has reported on it – or they’re from projects, like there’s the COVID Tracking Project that’s produced by The Atlantic magazine. There’s the COVID-19 Dashboard that I think all of us use that is from Johns Hopkins University. And even these are sort of lacking. The COVID-19 Tracking Project has loudly said they want more data. They’re not perfect. The Atlantic is often thought of as a kind of liberal magazine, so this might not appeal in conservative areas, so it’s really much better for the government to put it out. To tell you the extent of the problem, the former head of the CDC, along with multiple associations like the American Public Health Association, has put out a report about the information that they would like to see states and counties publically report. They’ve sort of given up on the federal government, but they’re saying this is what states could do and they have a list of 9 essential indicators and a total of 15 other ones that would be nice.

Noah Baker

If we take a step out of the United States, there are governments around the world that are collecting this data in a really efficient and effective way. And then presenting it in dashboards that the public can look at and use to help inform their day to day activities, even to the point of, ‘Should I go to this particular ice cream store because is there likely to be transmission there?’

Amy Maxmen

Yeah, I mean, it's really kind of fun for this story. I looked at dashboards of different places, and the ones that really stood out to me, were Singapore, New Zealand and South Korea. They post a number of the indicators about how bad is transmission per area, and that's a really important number. You don't want to just know how bad is it in a state or in a province. You want to have even more kind of granular data. And you don't want to know how many cases so far. You want to know how many right now and is it rising? What are the trends? So, in addition to those, they also report data on exposures. One of the prettiest ones I saw is in Singapore. They've got this really beautiful diagram that looks like some kind of like geometric fractal design or something where they have all the cases. You can see clusters. Here's a church and then there are 15 cases around that. You can see a line drawn from one of those cases to a store and then a little cluster at the store. So, you really get this beautiful look at how the disease is spreading and where, and that comes attached to a report that's very specific about, okay, this dormitory has an outbreak. We have this many people that have been tested, this number has tested positive, this number is quarantined right now, and this number of people are out of quarantine. So, you really get a very good sense of what's going on.

Noah Baker

And these kind of complete data are also really important for broader policy as we've mentioned, and I think that's kind of really exemplified by what's happening in New Zealand right now. So, for some time, New Zealand managed to completely eradicate coronavirus. As far as they could see, they weren't getting any positive tests for a period of time. And then they had coronaviruses imported back. And as long as they were catching one case at a time and it was being imported one person at a time, then you can keep control of it. But as soon as you start getting domestic transmission happening again then that's when you need to respond and they locked back down again. But the only way they can do that is because they have this comprehensive data. They know enough about where everything is to know when something's an imported case or know when it's a locally transmitted case or, most worryingly, it's come from somewhere that they don't know where it came from.

Amy Maxmen

Yeah, so had their new cases clearly been two people that travelled out of the country, and that was it, maybe they wouldn't have needed to lockdown, but what they realised is that they had this cluster and it didn't really link back to a known point of introduction, so that's why they decided to do a lockdown. But the point is, they knew that it was unknown because a lot of things are known and they're locking down but they're not just doing that. They're also doing a big investigation. They've quarantined a lot of people. They're even going to be doing genomic sequencing to kind of see is this strain related to other strains that are in the country or is it unrelated? Is it related to strings outside of the country? So, they're going to be doing some deep investigations there and hopefully ending it pretty quickly.

Noah Baker

And I suppose it’s worth saying that New Zealand is a much smaller country than the United States, in terms of populace and so on, but they're still going fully evidence-based and fully public health response first. It's really interesting to watch how it's playing out and how much success they're having.

Amy Maxmen

I think it is true. Countries that are smaller or countries that have smaller outbreaks, surely, they're able to do this, like ‘We know where 95% of cases are coming from.’ But that said, I don't think it's a good excuse for the US not doing it because even if we knew where a quarter of our cases were coming from, that could tell us quite a lot about where transmission happens.

Noah Baker

So, we've talked a lot about what's not being done. Do you have any reason based on the people you’ve spoken to and the reporting you've done to believe that any more will be done at any point in the future? Or is it people in the States are going to have to live without these data that could potentially be useful in all the ways we've said it could be useful?

Amy Maxmen

The CDC puts out reports at least weekly in their journal called Morbidity and Mortality Weekly Reports. I always find them really interesting. They're kind of these post-mortem analyses where they look at a bunch of data. And so those are sort of helpful, and I guess as those come out, we'll learn a little bit more, but they come out painfully slowly. A report about how there was a sleepaway camp in Georgia where more than 220 staff and campers were infected was about a camp in June and it didn't come out until August. So, I guess in a few months we'll have a little bit more data from them about how it's spreading, but they're very bittersweet because they don't come out in the time period that you could actually act on it and do something about it. So, that's what's really frustrating and, as of now, I don't see that changing right now.

Noah Baker

Yeah, I can kind of dream of a system in the future where there may be a granular enough dashboard to reflect what currently happens with Nature's offices around the world. We have a nice colour coding system. Our offices can be red or amber or green, depending on the level of threat at each office and whether or not we should go in and they have rules associated with them, and I have to say, well done, facilities departments at Nature. It's very easy system to read and I know whether or not I should go to the office or not. It would be great if I had that for cities in the UK. I find that super useful.

Amy Maxmen

Yeah, as would superintendents of school districts. They would love to know are they going to be endangering their teachers and students by saying that today is going to be a day we come into classes?

Noah Baker

Yeah, I think that would be super useful. If only we had one.

Host: Benjamin Thompson

Agreed. Well, let's call it there then, both, for another edition of Coronapod, and I hope you'll both join me in seven days for the next instalment. Amy and Noah, thank you so much.

Amy Maxmen

Thank you.

Noah Baker

Cheers, Ben.

Host: Shamini Bundell

And there’ll be more from the Coronapod team next week. Coming up, we'll be hearing about the two liquid states of sulfur. Before that, though, Dan Fox is here with this week's Research Highlights.

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Dan Fox

By mining medical records and genome sequences, scientists have identified a form of autism characterised by unusual levels of fat molecules in the blood. In the United States, nearly 2% of children are diagnosed with autism spectrum disorder (ASD). Genome studies suggest that there are different subtypes of ASD influenced by mutations in distinct sets of genes. Some of these genes are involved in processing fatty molecules called lipids, and the analysis of the medical records suggested that a subset of people diagnosed with ASD also have altered levels of blood lipids. It’s hoped that by identifying such ASD subtypes, researchers could create targeted interventions for the condition. Read that research in full at Nature Medicine.

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Dan Fox

When it comes to adopting solar energy, self-interest might prove a stronger motivator than the common good. A team of researchers assessed the outcome for a grassroots campaign to convince people to outfit their homes with solar panels. During the campaign, they trialled two different approaches, and found that people were twice as likely to install solar panels when exposed to messages focused on personal financial perks than when campaigns emphasised the community benefits of solar power. Messages with a focus on self-interest worked best among high-income households. However, people exposed to the community-based campaigns who installed solar panels were happier with their choices and more likely to recommend solar energy to their friends and neighbours. The team hopes the findings could help policymakers to develop programmes that make solar energy attractive to as many people as possible. Decide which approach appeals to you by reading the research in full at Proceedings of the National Academy of Sciences of the United States of America.

Host: Nick Howe

Next up, reporter Adam Levy is investigating an unusual transformation.

Interviewer: Adam Levy

A phase transition is when a material shifts suddenly from one state to another. That's something that I think most of us can relate to. I know my own life seems to have had a pretty dramatic phase transition thanks to the events of 2020. For a material, though, that means, for example, changing from liquid to solid due to changes in something like temperature.

Interviewee: Mohamed Mezouar

You go from one phase to another phase, from liquid to solid or other phase transitions, just by changing one external parameter.

Interviewer: Adam Levy

This is physicist Mohamed Mezouar. So, if you've ever watched an ice cube melt in a glass, then you've observed a phase transition.

Interviewee: Mohamed Mezouar

Yes, yes. In the whiskey or in the water.

Interviewer: Adam Levy

Normally, one thinks of a phase transition like this – going from one material state, for example, solid, to a very different one, for example, a liquid. But in a study out this week, Mohamed was investigating a phase transition between a liquid and another liquid. I called him up to find out what this actually means.

Interviewee: Mohamed Mezouar

People were not thinking that it will be possible. And actually, one experiment convinced that this is actually possible, and it showed a phase transition between two distinct liquids in phosphorus. The atomic elements are very different in one state and in another state. It’s like if you see from the liquid water and the solid water, the atoms and the chemical bonds between those are very different.

Interviewer: Adam Levy

So, normally, when I think about a liquid, I think about molecules all floating around. So, is it then that in sulphur, which is the substance that you were looking at, that the molecules floating around are different in the two different liquid states?

Interviewee: Mohamed Mezouar

Yes, definitively. In one liquid, it is made of sort of eight molecules, so eight atoms of sulphur that are in a ring, and on the other side, it's a long chain of atoms. The two liquids have also very different physical properties, optical properties, mechanical properties. All the properties are modified.

Interviewer: Adam Levy

So, you wanted to investigate the transition from one of these liquid states to the other. Now, what does this experiment actually look like? What are you actually physically doing to investigate this?

Interviewee: Mohamed Mezouar

So, it’s a very simple experiment where you put the sulfur sample in a high-pressure, high-temperature vessel. You just increase the pressure and the temperature. With X-rays, you can actually determine the structure of the material so we X-ray, and we can determine the structure of the sample at different pressure and temperature conditions. The main measurement of this work was the density, and what we saw is by gently increasing the pressure at one point, we observed the density jump. And so, this density jump was really the signature of two different states.

Interviewer: Adam Levy

So, liquid-liquid transitions have been seen before in phosphorus, but you also found evidence of something that's not been seen before, which is a critical point between this liquid-liquid transition. What is a critical point?

Interviewee: Mohamed Mezouar

Before the critical point, you have two systems that are separated and at this precise point, the two systems basically refuse to coexist, and you have divergence of most of the physical properties. Basically, the system becomes crazy at the critical point, and then when you go away from the from the critical point, everything comes back to a calm situation where you have one single state.

Interviewer: Adam Levy

And what was your reaction at finding evidence of this critical point for the first time in a transition from liquid to liquid?

Interviewee: Mohamed Mezouar

In the beginning, we thought this was an artefact because we saw some very big fluctuations and I said, ‘Oh, maybe we had some electronic problems.’ And we repeated three or four times the same experiments, and we've found exactly the same thing. And we were very excited about this because this was the first evidence for such a critical point. I think the excitement of the discovery was not immediate. We didn't jump out of the chair. We were just puzzling ourselves like, ‘What is going on here?’ And then in the second step, we jumped out our chair. We found out, but it was delayed, yeah, by a few days.

Interviewer: Adam Levy

Had to be sure before you could do any jumping.

Interviewee: Mohamed Mezouar

Yes, yes, yes.

Interviewer: Adam Levy

So, understanding this liquid-liquid state for sulphur, it's not just about learning about what happens for sulphur. It also teaches us about the physics of other materials.

Interviewee: Mohamed Mezouar

That's probably the most important thing, is we proved that it exists in sulphur, so it might also exist in other systems.

Interviewer: Adam Levy

And one of those materials would be one of the most fundamental materials there are, which is water.

Interviewee: Mohamed Mezouar

It’s extremely important for the physics of water because there are many anomalies in the physical properties. And one of the theories is based really on the existence of a critical point in the liquid state. Proving that you have a critical point in sulphur might give some grounds to the possibility of the existence of a critical point in water and this would validate important theories.

Interviewer: Adam Levy

How do you feel then about the future of this area of research?

Interviewee: Mohamed Mezouar

It's great. There's still a lot of things to do. Like always, in physics, when you find something that is very particular, you always find something more general behind. So, there is lots of things that are not really explained. In this field, it seems like an old field of research but actually there is still very important questions that are not yet resolved. We don't know, for example, how a solid melts. This is something that is still an open question. We don't know why we have this liquid-liquid transition in only two systems. And this is all related topics, and by looking at those particular systems can give us a lot of information about very, very important and old unsolved problems.

Host: Nick Howe

That was Mohamed Mezouar of the European Synchrotron Radiation Facility in Grenoble, France. A few years ago, Nature made a film showing what it's like working around the clock in this synchrotron, so you can find the link to that, along with Mohamed's paper, in the show notes.

Host: Shamini Bundell

Finally, on the show, it's time for the weekly Briefing chat, where we discuss a couple of articles that have been highlighted in the Nature Briefing – that's Nature's daily pick of science news and stories. So, Nick, what has caught your attention this time?

Host: Nick Howe

So, I was reading a story about how English is, ironically, the lingua franca of science.

Host: Shamini Bundell

And how did actually English become the lingua franca of science and not you know, French, say?

Host: Nick Howe

Well, it's currently the most commonly used language in science, but it wasn't always the case. In the early 20th century, a lot of science was actually done in German, but then after World War I and the rise of the US, a lot more science was done in English, and then because these were the places where science was done and where English was widely spoken, then it just sort of over time became the default language. And the top 50 journals are all in English, and 49 of those top 50 are based in either the US or the UK. So, yes, it's kind of just because, historically, this is where a lot of science was done and over time, English was just the way you communicate with other scientists.

Host: Shamini Bundell

And so, what impact does that have today on the way that science is done?

Host: Nick Howe

Well, in some ways, it's a big positive because if you are communicating with scientists across the globe, you can communicate in English and with some certainty that they'll be able to also communicate with you. I mean, our jobs kind of rely on that. We talk to scientists across the world and we normally do so in English. But the problem with this is it's quite exclusionary. A lot of people do not speak English and those people can be excluded from the scientific conversation. So, this article in Symmetry discusses a few different scientists from across the world who do not have English as the native language, and it talks about their experiences. And one is a science communicator, and she actually really struggled to communicate in her native language about science because she was so used to talking about it and discussing it in English. And there are also some cases where people who have accents when they speak English, they get comments about it, they have problems at conferences and things like that, just because there is this emphasis on English and English spoken pretty much with US or a UK dialect.

Host: Shamini Bundell

Okay, so one problem is like exclusion within science itself in terms of things being then more difficult for people who want to publish if it's not their native language or like maybe they're just sort of general career and the way other people perceive them, but also exclusionary to like members of the public, like non-English-speaking members of public who need to know the science and the results of science and are then cut off from a lot of it.

Host: Nick Howe

Yeah, exactly. So, as I say, one of the people in this story was a science communicator, and she said that people think that we don't care because we're not talking about it in their native language, but you only actually get involved in these conversations if you have English in the first place. So, it is a problem in parts of the world where English isn't as widely spoken, or if people just don't have access to learning English to get into science in the first place. Because of this emphasis on English being the lingua franca, if you're unable to learn it or you don't have access to the resources to do so, then science may be an inaccessible career for you. But what have you found this week, Shamini?

Host: Shamini Bundell

Right, so another awesome biology story – transparent squid!

Host: Nick Howe

Aren’t squid transparent anyway?

Host: Shamini Bundell

Okay, you have a point. The little baby ones, in particular, are pretty transparent, yes. However, squids do have a lot of colour and patterns in their skin, and if you've ever seen videos, they do that flickery thing because they have all these little pigment-containing cells and they can turn them on and off and create patterns really quickly that go all across their bodies.

Host: Nick Howe

Alright, so maybe I'm being a bit picky then. So, what's up with these transparent squid?

Host: Shamini Bundell

Okay, so the important thing about this is why they're transparent, and that is because they are genetically modified. They have had a gene, a sort of pigment-creating gene, knocked out with CRISPR-Cas9, and this is the first time that that has been used on a squid.

Host: Nick Howe

So why was the squid chosen and what purpose does it have being transparent?

Host: Shamini Bundell

Well, squid are awesome. I mean, I know I say that about every single animal that ever comes up because all animals are awesome, but squid are useful in science, particularly for a lot of research on neurons. They have really big neurons and really complex nervous systems, so they are already sort of potentially a model organism for that kind of research. But in order to be a model organism, the really helpful thing to be able to do would be to genetically modify them, knock out this gene, put in some fluorescent marker here, there and everywhere, and that's been kind of tricky up until now, partly because the developing embryos have a hard outer shell, which made it really hard to get the CRISPR-Cas9 protein inside them in order to genetically modify them.

Host: Nick Howe

And so how did they overcome this problem?

Host: Shamini Bundell

Just really, really small scissors, basically.

Host: Nick Howe

Laughs.

Host: Shamini Bundell

I'm not even joking. They physically cut through this outer sort of tough layer really carefully, because if you cut it too much, everything's going to leak out – not good – but just a little cut so that you can then put a very tiny needle with the injection through the hole into the embryo. And then they have little baby squids and the –squid or squids, I don't know – but you can see the normal ones are sort of slightly dotty with bits of pigmentation and the genetically modified ones don't have those dots and are even more see-through.

Host: Nick Howe

So, I guess this is going to open up a whole avenue of interesting neuroscience type research?

Host: Shamini Bundell

Well, I think that's what the researchers are hoping. They've just sort of tried it, at this point, with one type of squid, which is not necessarily one that's easy to grow to adulthood in the lab, so they might need to try on a different one and try out different sort of genetic modifications, but this sort of proof of principle and this new technique for doing it will hopefully be useful for neuroscience research in particular.

Host: Nick Howe

Well, I'm going be transparent with you, Shamini. It is time for the end of the Briefing, but thanks for chatting to me. And listeners, if you'd like more stories like these, then make sure you check out the Nature Briefing. We'll put a link of where to sign up and links to today's stories in this week's show notes.

Host: Shamini Bundell

That's all for this week. As always, if you want to get in touch with us, then you can reach out on Twitter – we're at @NaturePodcast – or send us an email to podcast@nature.com. I'm Shamini Bundell.

Host: Nick Howe

And I’m Nick Howe. See you next time.